Don't know exactly what you are saying, but if you are using encryption, don't.
Straight up Exfat is what you want.
Some Sandisk USB drives come with proprietary encryption software. I call it "built in". It only works on Sandisk USB devices.
I've used them to back up our laptops, which I double encrypt. Encrypt the files/folders on the laptop first, then re-encrypt as they copy to the USB drives, for "offsite" storage. If I ever lose one, the odds of someone breaking 2 types of encryption are slim to none. Maybe the FBI could figure it out, like they broke into the iPhone of an LA mass killer years ago.
So, I first tried using some old Sandisk USB drives that come with the encryption software.
In all 3 formats, exFAT, NTFS, and FAT32.
None of them worked in the C8.
So, read a few other websites, and started to think maybe the Sandisk USB stick was the problem, tried some old spare vanilla no name USB 32GB devices, also formatted in exFAT, NTFS, and FAT32.
Only the FAT32 formatted USB drive is recognized in my Infotainment system (keep in mind, mine is a 2024, and is supposedly different from the prior years).
So, if you have a 2024 C8, FAT32, and a non Sandisk with encryption software drive works. For me.
The other options didn't. Just to clarify, I didn't use the encryption on the music files or the devices.
All were formatted, which supposedly erases everything, but not on a Sandisk encryption device, apparently.
Windows quick format just wipes the VTOC afaik. There is something extra on those encryption capable USB drives that the C8 Infotainment system didn't like.
I spent a few days on the US CF trying different combos, with a guy on there that also said try exFAT, I did, but it doesn't work in my 2024. FAT32 does.
My GM Android system is back leveled (Android 10) so maybe that has something to do with it, but I doubt it. My phones are Android 13, by comparison.